Processing factors of triadimefon and triadimenol in barley brewing based on response surface methodology

Numerous studies have focused on the effects of food-processing techniques on pesticide residues. However, it remains a challenge to ensure high-quality processing and effective pesticide removal from foods. Triadimefon (TF) is a broad-spectrum fungicide that is widely used in barley crop, and its residues are detected in its products, including beer. In this study, we investigated the dissipation kinetics of TF during fermentation mediated by two different yeast strains, Saccharomyces cerevisiae IAPPST 1401 (Y1) and. CICC 1202 (Y2), and found that Y2 promoted the degradation of TF. Response surface methodology was used to optimize fermentation process variables, in order to achieve the maximum removal rate of TF and the minimum production of its corresponding metabolite, triadimenol (TN). Processing factors (PFs) were also evaluated during the optimized brewing process and were close to 1 for TF during the malting, milling, boiling, and cooling steps, but not in mashing and fermentation that were 0.19 and 0.13, respectively. TF degraded to TN during brewing, and a PF value of >1 for TN was also observed in malting and fermentation. Our analysis concluded that beers produced using the yeasts and brewing methods we investigated are safe for human consumption. (C) 2015 Elsevier Ltd. All rights reserved.